Renewal of funding is requested to train research scientists in the behavioral aspects of mental retardation and other developmental disabilities. The proposed program represents a continuation of the mental retardation research training program begun at Peabody College in 1954. The basic goal of this program is to train sophisticated, broadly based, skillful behavioral scientists committed to research on mental retardation and other developmental disabilities. The behavioral manifestation of developmental disabilities, the complex multifaceted interactions between behavioral and biomedical variables, and the increasing prevalence of contributing risk factors, strongly support the need for sophisticated research training at the pre- and postdoctoral level. The training program will emphasize the complex, interdisciplinary nature of contemporary behavioral research in mental retardation and other developmental disabilities in several ways: (a) trainees will come from the Departments of Psychology and Human Development, Special Education and Speech and Hearing Sciences; (b) training faculty will include research scientists studying a wide range of problems; (c) trainees will be immersed in ongoing, collaborative research; (d) through required coursework, a continuing Proseminar, and a diverse colloquium program, trainees will receive a comprehensive introduction to contemporary behavioral research as well as relevant research in the neuro and biomedical sciences. Funds are requested for 6 predoctoral and 2 postdoctoral trainees. The program builds on the present training program, existing resources and programs within the Vanderbilt University community, and the rich ongoing tradition of behavioral research in mental retardation of the John F. Kennedy Center for Research on Human Development.